Quickstart: Build a Java app to manage Azure Cosmos DB SQL API data

This quickstart shows you how to use a Java application to create and manage a document database from your Azure Cosmos DB SQL API account. First, you create an Azure Cosmos DB SQL API account using the Azure portal, create a Java app using the SQL Java SDK, and then add resources to your Cosmos DB account by using the Java application. The instructions in this quickstart can be followed on any operating system that is capable of running Java. After completing this quickstart you'll be familiar with creating and modifying Cosmos DB databases, containers in either the UI or programmatically, whichever is your preference.

Prerequisites

If you don't have an Azure subscription, create a free account before you begin.

You can Try Azure Cosmos DB for free without an Azure subscription, free of charge and commitments. Or, you can use the Azure Cosmos DB Emulator with a URI of https://localhost:8081. For the key to use with the emulator, see Authenticating requests.

In addition:

  • Java Development Kit (JDK) version 8
    • Be sure to set the JAVA_HOME environment variable to point to the folder where the JDK is installed.
  • Download and install a Maven binary archive
    • On Ubuntu, you can run apt-get install maven to install Maven.
  • Git
    • On Ubuntu, you can run sudo apt-get install git to install Git.

Create a database account

Before you can create a document database, you need to create a SQL API account with Azure Cosmos DB.

  1. Go to the Azure portal to create an Azure Cosmos DB account. Search for and select Azure Cosmos DB.

    The Azure portal Databases pane

  2. Select Add.

  3. On the Create Azure Cosmos DB Account page, enter the basic settings for the new Azure Cosmos account.

    Setting Value Description
    Subscription Subscription name Select the Azure subscription that you want to use for this Azure Cosmos account.
    Resource Group Resource group name Select a resource group, or select Create new, then enter a unique name for the new resource group.
    Account Name A unique name Enter a name to identify your Azure Cosmos account. Because documents.azure.com is appended to the ID that you provide to create your URI, use a unique ID.

    The ID can only contain lowercase letters, numbers, and the hyphen (-) character. It must be between 3-31 characters in length.
    API The type of account to create Select Core (SQL) to create a document database and query by using SQL syntax.

    The API determines the type of account to create. Azure Cosmos DB provides five APIs: Core (SQL) and MongoDB for document data, Gremlin for graph data, Azure Table, and Cassandra. Currently, you must create a separate account for each API.

    Learn more about the SQL API.
    Location The region closest to your users Select a geographic location to host your Azure Cosmos DB account. Use the location that is closest to your users to give them the fastest access to the data.

    The new account page for Azure Cosmos DB

  4. Select Review + create. You can skip the Network and Tags sections.

  5. Review the account settings, and then select Create. It takes a few minutes to create the account. Wait for the portal page to display Your deployment is complete.

    The Azure portal Notifications pane

  6. Select Go to resource to go to the Azure Cosmos DB account page.

    The Azure Cosmos DB account page

Add a container

You can now use the Data Explorer tool in the Azure portal to create a database and container.

  1. Select Data Explorer > New Container.

    The Add Container area is displayed on the far right, you may need to scroll right to see it.

    The Azure portal Data Explorer, Add Container pane

  2. In the Add container page, enter the settings for the new container.

    Setting Suggested value Description
    Database ID Tasks Enter ToDoList as the name for the new database. Database names must contain from 1 through 255 characters, and they cannot contain /, \\, #, ?, or a trailing space. Check the Provision database throughput option, it allows you to share the throughput provisioned to the database across all the containers within the database. This option also helps with cost savings.
    Throughput 400 Leave the throughput at 400 request units per second (RU/s). If you want to reduce latency, you can scale up the throughput later.
    Container ID Items Enter Items as the name for your new container. Container IDs have the same character requirements as database names.
    Partition key /category The sample described in this article uses /category as the partition key.

    In addition to the preceding settings, you can optionally add Unique keys for the container. Let's leave the field empty in this example. Unique keys provide developers with the ability to add a layer of data integrity to the database. By creating a unique key policy while creating a container, you ensure the uniqueness of one or more values per partition key. To learn more, refer to the Unique keys in Azure Cosmos DB article.

    Select OK. The Data Explorer displays the new database and container.

Add sample data

You can now add data to your new container using Data Explorer.

  1. From the Data Explorer, expand the Tasks database, expand the Items container. Select Items, and then select New Item.

    Create new documents in Data Explorer in the Azure portal

  2. Now add a document to the container with the following structure.

    {
        "id": "1",
        "category": "personal",
        "name": "groceries",
        "description": "Pick up apples and strawberries.",
        "isComplete": false
    }
    
  3. Once you've added the json to the Documents tab, select Save.

    Copy in json data and select Save in Data Explorer in the Azure portal

  4. Create and save one more document where you insert a unique value for the id property, and change the other properties as you see fit. Your new documents can have any structure you want as Azure Cosmos DB doesn't impose any schema on your data.

Query your data

You can use queries in Data Explorer to retrieve and filter your data.

  1. At the top of the Documents tab in Data Explorer, review the default query SELECT * FROM c. This query retrieves and displays all documents in the collection in ID order.

    Default query in Data Explorer is SELECT * FROM c

  2. To change the query, select Edit Filter, replace the default query with ORDER BY c._ts DESC, and then select Apply Filter.

    Change the default query by adding ORDER BY c._ts DESC and clicking Apply Filter

    The modified query displays the documents in descending order based on their time stamp, so now your second document is listed first.

    Changed query to ORDER BY c._ts DESC and clicking Apply Filter

If you're familiar with SQL syntax, you can enter any supported SQL queries in the query predicate box. You can also use Data Explorer to create stored procedures, UDFs, and triggers for server-side business logic.

Data Explorer provides easy Azure portal access to all of the built-in programmatic data access features available in the APIs. You also use the portal to scale throughput, get keys and connection strings, and review metrics and SLAs for your Azure Cosmos DB account.

Clone the sample application

Now let's switch to working with code. Let's clone a SQL API app from GitHub, set the connection string, and run it. You'll see how easy it is to work with data programmatically.

  1. Run the following command to clone the sample repository. This command creates a copy of the sample app on your computer.

    git clone https://github.com/Azure-Samples/azure-cosmos-java-getting-started.git
    

Review the code

This step is optional. If you're interested in learning how the database resources are created in the code, you can review the following snippets. Otherwise, you can skip ahead to Run the app .

  • CosmosClient initialization. The CosmosClient provides client-side logical representation for the Azure Cosmos database service. This client is used to configure and execute requests against the service.

    client = new CosmosClientBuilder()
        .setEndpoint(AccountSettings.HOST)
        .setKey(AccountSettings.MASTER_KEY)
        .setConnectionPolicy(defaultPolicy)
        .setConsistencyLevel(ConsistencyLevel.EVENTUAL)
        .buildClient();
    
    
  • CosmosDatabase creation.

    database = client.createDatabaseIfNotExists(databaseName).getDatabase();
    
  • CosmosContainer creation.

    CosmosContainerProperties containerProperties =
        new CosmosContainerProperties(containerName, "/lastName");
    
    //  Create container with 400 RU/s
    container = database.createContainerIfNotExists(containerProperties, 400).getContainer();
    
  • Item creation by using the createItem method.

    //  Create item using container that we created using sync client
    
    //  Use lastName as partitionKey for cosmos item
    //  Using appropriate partition key improves the performance of database operations
    CosmosItemRequestOptions cosmosItemRequestOptions = new CosmosItemRequestOptions(family.getLastName());
    CosmosItemResponse item = container.createItem(family, cosmosItemRequestOptions);
    
  • Point reads are performed using getItem and read method

    CosmosItem item = container.getItem(family.getId(), family.getLastName());
    try {
        CosmosItemResponse read = item.read(new CosmosItemRequestOptions(family.getLastName()));
        double requestCharge = read.getRequestCharge();
        Duration requestLatency = read.getRequestLatency();
        System.out.println(String.format("Item successfully read with id %s with a charge of %.2f and within duration %s",
            read.getItem().getId(), requestCharge, requestLatency));
    } catch (CosmosClientException e) {
        e.printStackTrace();
        System.err.println(String.format("Read Item failed with %s", e));
    }
    
  • SQL queries over JSON are performed using the queryItems method.

    // Set some common query options
    FeedOptions queryOptions = new FeedOptions();
    queryOptions.maxItemCount(10);
    queryOptions.setEnableCrossPartitionQuery(true);
    //  Set populate query metrics to get metrics around query executions
    queryOptions.populateQueryMetrics(true);
    
    Iterator<FeedResponse<CosmosItemProperties>> feedResponseIterator = container.queryItems(
        "SELECT * FROM Family WHERE Family.lastName IN ('Andersen', 'Wakefield', 'Johnson')", queryOptions);
    
    feedResponseIterator.forEachRemaining(cosmosItemPropertiesFeedResponse -> {
        System.out.println("Got a page of query result with " +
            cosmosItemPropertiesFeedResponse.getResults().size() + " items(s)"
            + " and request charge of " + cosmosItemPropertiesFeedResponse.getRequestCharge());
    
        System.out.println("Item Ids " + cosmosItemPropertiesFeedResponse
            .getResults()
            .stream()
            .map(Resource::getId)
            .collect(Collectors.toList()));
    });
    

Run the app

Now go back to the Azure portal to get your connection string information and launch the app with your endpoint information. This enables your app to communicate with your hosted database.

  1. In the git terminal window, cd to the sample code folder.

    cd azure-cosmos-java-getting-started
    
  2. In the git terminal window, use the following command to install the required Java packages.

    mvn package
    
  3. In the git terminal window, use the following command to start the Java application (replace YOUR_COSMOS_DB_HOSTNAME with the quoted URI value from the portal, and replace YOUR_COSMOS_DB_MASTER_KEY with the quoted primary key from portal)

    mvn exec:java -DACCOUNT_HOST=YOUR_COSMOS_DB_HOSTNAME -DACCOUNT_KEY=YOUR_COSMOS_DB_MASTER_KEY
    
    

    The terminal window displays a notification that the FamilyDB database was created.

  4. The app creates database with name AzureSampleFamilyDB

  5. The app creates container with name FamilyContainer

  6. The app will perform point reads using object ids and partition key value (which is lastName in our sample).

  7. The app will query items to retrieve all families with last name in ('Andersen', 'Wakefield', 'Johnson')

  8. The app doesn't delete the created resources. Switch back to the portal to clean up the resources. from your account so that you don't incur charges.

Review SLAs in the Azure portal

The Azure portal monitors your Cosmos DB account throughput, storage, availability, latency, and consistency. Charts for metrics associated with an Azure Cosmos DB Service Level Agreement (SLA) show the SLA value compared to actual performance. This suite of metrics makes monitoring your SLAs transparent.

To review metrics and SLAs:

  1. Select Metrics in your Cosmos DB account's navigation menu.

  2. Select a tab such as Latency, and select a timeframe on the right. Compare the Actual and SLA lines on the charts.

    Azure Cosmos DB metrics suite

  3. Review the metrics on the other tabs.

Clean up resources

When you're done with your web app and Azure Cosmos DB account, you can delete the Azure resources you created so you don't incur more charges. To delete the resources:

  1. In the Azure portal, select Resource groups on the far left. If the left menu is collapsed, select Expand button to expand it.

  2. Select the resource group you created for this quickstart.

    Select the resource group to delete

  3. In the new window, select Delete resource group.

    Delete the resource group

  4. In the next window, enter the name of the resource group to delete, and then select Delete.

Next steps

In this quickstart, you've learned how to create an Azure Cosmos account, document database, and container using the Data Explorer, and run an app to do the same thing programmatically. You can now import additional data into your Azure Cosmos container.